I'm not big on C, so let's parse this together. If the gun is using stock sights (a gun sight adds the disable sights flag) and at the same time the effective dispersion (perception/eye encumberance) is smaller than your recoil penalty (i assume something like you're not getting shaken up), then how much it costs you per turn to steady, and thus, for how long can you 'aim down' before maxed out, is modified by:

So it's impossible to create quick-aiming bulky (but not heavy) weapons like bows (unsighted) without making their volume tiny and cheesing the inventory. Would this not be better as a function of volume AND weight? Or just modify it a tad since we assume this was meant for pistols/SMGs or small shotguns/carabines.

LE: Values with 7 of Hand encumberance, so one single tier of penalty because of that, but the progression remains true even then.